Inevitably, if you're active in your home or small business
metalworking shop, the day comes when the mini-mill is undersized
and/or underpowered for some task that is at hand. On those days, we start to daydream
about a bigger mill; not necessarily a big, 1-ton Bridgeport knee mill, but just a scaled up version of the
mini-mill or something similar, for under $1000. Generally, the next step up has been to
one of the Rong-Fu
style, round-column mill-drills, but now there's another option to consider...

Over a year ago, Sieg
introduced a new mid-size mill, the X3 model, that
looked like a good fit, in size, weight and price, for those requiring something a bit
bigger than the mini-mill.

Sieg X3 mid-size mill
with 1-2-3 blocks for scale

Until recently, Lathemaster has been the only U.S. distributor for
the X3. Lathemaster has earned a good reputation for delivering and supporting the X3, and
there are several good web
sites by those pioneers who purchased their X3 mills from them. At the start of 2006,
Grizzly added the X3 to their catalog as P/N 0463, and there are rumors that Harbor Freight may also offer it.

Update: 03/09/06The rumors are true: HF now lists the X3 mill on
their web site as P/N 93885End of update

About a year ago, I reached that stage where I "had to
have" a larger lathe and mill. Construction work on my new shop was just about
finished, and for the first time, I had enough space to accommodate these larger tools. I
had an opportunity to order the X3 mill and C6 lathe directly from Sieg. Unfortunately, not too long
after I received them, I was diagnosed with a brain aneurysm and the required surgery set
back my time schedule by a bit. My brain seems to be working OK now, far as I can
tell, and I'm getting back into a regular routine in the shop and working on the web site.
With the prospect of wider distribution of the X3 mill in the U.S., this seemed like a
good time to do the review I had planned to do a year ago.

I'm going to break my tradition by describing the shipping,
cleanup and setup at the end of the article, instead of the beginning. So if you really
like things in chronological order, start here.

The head contains the drive gears and quill components.The head and motor
assembly move up and down the dovetail column under control of the Z-axis handwheel. These
controls are explained in detail in the Column and Z-Axis Control section.

Similar to Bridgeport-style mills, the head has an extendable quill that holds
R8 tooling (Note: apparently there are also versions that use a #3 Morse Taper.) About 2
3/8" in diameter, the quill can be extended up to 3 1/4" and can be locked in
position anywhere within this range by means of the locking lever on the front of the
head.

A 3-arm handwheel extends and retracts the quill and can be used for
drilling operations much like a drill press. A dial calibrated in divisions of 0.04"
accurately tracks the motion of the quill and the knurled ring can be rotated to establish
a zero setting.

Located above and behind the handwheel is the Hi/Lo-range gear selector. The
legend on the front of the headstock lists the LO range as 100-1000 RPM and HI range as
100-2000. As with all such gear arrangements, LO range provides increased torque for heavy
cutting operations. The central position of the knob is Neutral, in which the quill is
decoupled from the gear train. This setting could potentially be useful for rotating the
quill manually for fine drilling or tapping operations.

End mills can be held either in end-mill adapters or in R8 collets. I like the E/M adapters for
general use, and reserve the collets for when a few inches of extra headroom is required.
Here's a selection of collets, E/M adapters and a boring head.

R8 tooling - end
mill adapters, collet, boring head

The only tooling included with the mill is a nicely finished 3-16mm (1/2")
drill chuck with R8 adapter, so be sure to have your end mill adapters and/or collets,
milling vise, etc. on order in time for the mill's delivery.

3-16mm chuck included
with X3 mill

A press-fitted black plastic safety cap covers the rotating shaft that extends
out the top of the head. Removing the cap provides access to the top end of the quill
shaft and drawbar. R8 tooling has a slot that runs lengthwise along the tool shaft. The
slot engages with a pin inside the quill, so you must rotate the quill until they engage.
Then the tool is drawn tightly into the quill by tightening the drawbar. Due to the
relative steepness of the R8 taper, a light tap on the head of the drawbar with a small
brass hammer usually is sufficient to break the taper free when removing the tooling. By
contrast, tooling held by a #3 Morse Taper sometimes requires more testosterone
during the removal process.

The top part of the head is a separate casting that can be be removed by
loosening four cap-head screws. Doing so reveals the inner workings of the drive train,
which is a combination of belt- and gear-drive.

Head
cover casting

Spindle belt drive and
gear train

I was very pleased to see the belt drive. If you have read my reviews of the
mini-mill, or spent much time on any of the mini-lathe/mill interest groups on the Web,
you already know that one of the most common failure points of the mini-mill is the gear
train between the motor and spindle. The reason is that there is no component, other than
the gears, to absorb shock if the cutting tool digs in. When this occurs, the result often
is that the teeth on one or more of the gears in the drive train is sheared off. Not only
does this put the mill out of service for a while, replacing the gears is fairly
expensive. Note: I just received from Stirling Steele, a
belt-drive conversion kit for the mini-mill. I will be posting a review on this unit
soon.

If you are curious and decide to remove the cover over the motor, please note
that the screws holding the cover in place do not need to be removed completely. The
screws are accessed through the four holes in the top of the cover. Just loosen them up
and the cover can be slid off. I didn't discover this until removing the cover the hard
way - and losing one of the screws in the process.

The motor is mounted on the left side of the head. At 8" long X 3
1/2" diameter, it is about twice the size of the mini-mill's motor. I could not find
a HP rating on the motor, in the manual, or on the Sieg web site, but it is rated at 600
Watts. At 750 Watts per HP, this would make it about 3/4 HP, which is how it is rated by
Grizzly. In any case, the motor seems plenty powerful for the work I have tackled on
the mill so far.

Like the mini-mill and mini-lathe, the X3 mill has an electronic fully-variable
speed control. This is a little unusual on a motor this powerful, but I'm glad to have it
since I lack the patience to enjoy changing belts and pulleys for speed control. I
also like the ability to adjust the speed "on the fly" if it is obviously too
fast or too slow for what I'm doing. Located about mid-way up inside the black sheet metal
enclosure at the back of the mill, the motor control board is well protected from metal
chips, oil and cutting fluid.

Variable speed
solid-state motor controller

The speed control knob is mounted on the right-hand side of the enclosure for
the vertical column, near the back. Also located there are the power switch and
forward/reverse switch for the motor, and the fuse holder. I found this location to be
somewhat awkward. At 5' 6", I'm short of stature, and my arms are proportionately
foreshortened. If I stand directly in front of the mill with the Y-axis handwheel just
touching my stomach, and reach back to the controls with my right arm, the controls are
about 6" beyond my reach. Hmmm, maybe if I lost a few pounds..., nah, I still
couldn't reach 'em.

Electrical motor
controls on right side of column

This isn't too big a deal for two reasons: (1) Since the handwheels for the X
and Z axes are mounted off to the right side of the mill, I find that I stand off to that
side while working. This brings the electronic controls within reach. (2) It looks like it
would not be too difficult to relocate the variable speed control, or all of the
electrical controls, around to the front of the mill. I haven't tried this, but it
looks like a mod I'll try before too long.

In the photo above, the fuse holder is at the top, followed by the variable
speed control, the forward/reverse switch and the on/off switch. On other X3 web sites, I
have seen a slightly different configuration. There's also an emergency on/off switch
located on the front of the mill, on the left side of the head. The emergency switch turns
of the motor when you press in on it. I'ts designed as sort of a "panic button"
that you can mash down in an emergency to stop the mill motor.

If you then rotate the knob clockwise, as indicated by the arrows, the button
will pop back out to it's normal position and the yellow FAULT light comes on. When the
FAULT light is on, the FWD/REV or Power switch on the right side of the column must be
recycled to restart the mill. The FAULT light will also come on and the mill will
stop if the motor is stalled - for example by digging a tool too deeply into the
workpiece. Finally, the FAULT light will come on when power is restored after power is
interrupted at the wall socket - due to a circuit breaker tripping, a lightning storm or
any other cause. This prevents the mill from coming back to life unexpectedly when power
is restored to the circuit.

The head is raised or lowered on the dovetailed column by means of a leadscrew
located inside the column. The leadscrew is controlled by the Z-axis handwheel located on
the right side of the front of the mill base, and is supported by bearings at both ends
and by a backlash-limiting bearing where it engages with the head. Also located within the
column, a compressed gas strut, like you often see supporting hatch-back doors on cars,
offsets the weight of the head.

Rear of column
with sheet-metal housing removed

Top support bearing

Bottom support
bearing and bevel gears

Bearing and gas strut
attached to head support bracket

Steel yoke supporting
the head, and locking lever

The strut limits the downward range of movement of the the head. With the head
all the way down, the bottom of the spindle is about 5 1/4" from the surface of the
table. Although, in principle, it would be nice if the head could move down closer to the
table surface, I would not anticipate too many situations where this would matter. Even
when using a collet to hold a short cutting tool, the tip of the tool is within an inch of
the top of milling vise. The quill can also be extended up to 3 1/4" from the head,
bringing the tip of the cutting tool to within an inch of the table surface.

I suppose if this ever became a big problem for some reason, the strut could be
replaced with a counterweight system. In the Files section of the Lathemaster
Yahoo group, there's a file "X3 modifications.pdf" that illustrates
this modification. Or maybe just remove the gas strut? Interestingly, I noticed that the Grizzly site specifies a
range of 14 7/8" and the parts explosion in the manual does not show the gas strut.

As you can see in the photos above, the leadscrew that raises and lowers the
column is connected to the handwheel on the front of the mill by a pair of beveled gears.
The head's range of movement is about 9 1/2", with the face of the spindle about 14
3/4" from the table when the head is at the topmost position and about 5 1/4"
from the table at the lowest position. For routine work, the head can be positioned at a
convenient height above the milling vise and the spindle extended to contact the work, but
for maximum rigidity, it is best to have the quill fully retracted.

Machined from cast iron, the table is 6 1/4 x 21 3/4" in size. There are 3
slots for T-nuts, .470 wide and I found that the 7/16" (.4375") T-nuts that I
use on the mini-mill fit nicely. For those of you who may not be familiar with them,
T-nuts are special nuts, with a cross-section that looks like an inverted "T".
They fit within and can slide along the slots in the table and, for setups where a vise
will not work, are used to secure the work being milled to the table surface. Typically,
they are purchased as part of a set of clamping accessories designed for this purpose.

Along the front and back edge of the table are shallow channels for coolant
runoff. A screw-plug on the back left side of the table can be removed to attach a drain
for collecting the coolant.

Both the X- and Y- leadscrews are Imperial 10 TPI threads. On the X-axis, a
heavy cast-iron handle provides inertia to help keep the table moving smoothly and easily.
A decoupling connector is provided to disengage the handwheel when the optional
Sieg power feed is engaged. This keeps the handle from whipping around and knocking into
things - possibly including various parts of your body. The Y-axis handwheel is slightly
smaller and lighter than that on the X-axis, which is fine, since movements along the
Y-axis are typically fairly short.

Coupling for
disengaging X-axis handwheel

Nicely engraved and easily readable dials mark off the rotation into 100
divisions of 0.001" per division. This is a big improvement over the mini-mill, on which the 16 TPI leadscrews result in 62.5 divisions per
rotation making it an exercise in mental gymnastics to keep track of how far you have
moved the table when using the dials for reference (note: the Micro-Mark mini-mill is an exception, with 20 TPI leadscrews). The
calibrated dial can be rotated independently of the handwheel in order to set the dial to
zero and a nicely knurled rim provides a gripping surface to expedite this action. All of
the handwheels include ball bearing races for smooth action and reduced backlash.

Calibrated X-axis scale
(Y-axis is the same)

Bearing race for
smooth operation

A slot runs along the front side of the table, apparently for use with
automated stop or reverse switches used with the Sieg power feed. Below the slot is a
16" rule, centered on zero, for use when thousandths of an inch are more precision
than necessary.

A black locking lever can be engaged to lock the table to prevent movement in
the X direction. This comes in handy when drilling or any other operation where X-axis
motion is not needed and maximum rigidity and accuracy is desired. An identical lever for
locking the Y-axis is located below the right side of the table. A bonus feature of these
locking levers that may not be immediately apparent, is that they are spring-loaded and
can be adjusted so that they don't get in the way of other parts. To adjust, first tighten
slightly, then pull out on the handle and move it clockwise or counterclockwise to the
desired position, then release it. Here's a photo showing the internal parts of the
levers:

"Exploded"
view of locking lever

Along the front of the casting that supports the table are four gib screws and
locking nuts. For the uninitiated, gibs are strips of metal with a diamond-shaped
cross-section that are used in dovetail slides to take up any play. This minimizes any
side-to-side movement of the dovetail, and provides a way to keep the machine tight and
accurate as it wears in with use. When the screws are tightened, they press the gib strip
against one side of the dovetail slide. The trick is to get
the screws just tight enough to minimize any slop, but not so tight that they impede
the motion of the table.

Front of mill table
showing X-axis gib screws

Right side of mill base
showing Y-axis gib screws

At the left end of the table, the X-axis leadscrew is supported by a bearing.
The end-plates at both ends of the table include alignment pins that match up with holes
in the end of the table to ensure precise alignment. This feature helps to ensure that the
leadscrew is properly aligned along its entire length to prevent binding. The leadscrew
nuts for both the X- and Y-axes are machined from brass and have a slot cut into
them to allow adjustment for minimizing backlash as the nuts wear-in with use.

Since my machines were shipped directly from the Sieg factory in Shanghai, I
had to do some interaction with the importer and trucking company to get them through
customs and guide them to my garage door. Having never done this before, I found the
process a little arcane. If you can order the X3 directly from a U.S. distributor, you can
skip that part.

The X3 mill is too heavy for UPS delivery so be prepared for a fairly large
truck - up to semi-trailer size - to show up at your delivery address. If your location
won't accommodate a large truck, you'd be well advised to work this out with the shipper
in advance. One thing to watch out for: unless you specify otherwise, most trucking
companies will assume that they are delivering to a loading dock. If you are having the
mill delivered to your home or a location without a loading dock, be sure to specify that
it be delivered by a lift-gate truck - otherwise you will have no way to get the mill off
of the truck onto your driveway and into your shop.

X3 Mill and C6 Lathe in the
garage

I'm no expert on these matters, but my experience has been that the truck
driver generally is obligated only to get the box off the truck and onto the loading dock
(or driveway). If you are lucky, as I was, the driver may help you move the machine into
your shop, garage or other holding area, using a pallet truck. This can be a big help,
since moving a nearly 400 lb. shipping crate is usually not a trivial matter for the
average homeowner. If the driver does help you out, a $10 tip would be a nice gesture.

The mill is shipped in a wood crate and is bolted to a reinforced plywood and
particle board base. From the web sites I have read, X3 owners have all received their
mills without shipping damage, as did I. You'll need some tin snips to cut the metal bands
- or just twist them back and forth with pliers until metal fatigue breaks them apart. I
found a furniture dolly from Harbor Freight to be very useful for moving the machines
around until I could get them into their permanent locations. Since, in my case, this took
nearly a year, being able to move them out of the way was a big advantage.

All of the imported machine tools come coated with a generous layer of thick
wax-like grease to protect them from rust while in transit from China. Kerosene or WD-40
(in liquid, not spray form) are good choices to dissolve it and, along with some rags and chip brushes, is all you need to clean up the lathe. Elsewhere
on my site, I've gone into a lot of detail on cleaning up this gunk, so I won't go into a
blow-by-blow description here. After doing this type of work on the floor of the garage a
few times, I later smartened up and realized that it's a lot easier to do when the machine
is already up on the bench.

Note: My digital camera does not accurately record the red color of the mill.
Although it looks orange-red in the photos, the real color is a much deeper cherry-red or
blue-red. The picture of the mill on the dolly is pretty close to the real color.

The general procedure is first to clean up all of the grease visible on the
external surfaces of the machine. Everybody seems to have their own method, but I like to
use a 2" or 3" chip brush dipped in kerosene for this work, followed by a
cleanup with a cotton rag (this, of course, is what happens to all the used T-shirts
around my house.) After cleaning up the outside, the next step is to remove the table and
clean up the dovetails and leadscrews. I also removed the gib screws and lock nuts and
soaked them in the kerosene bucket for a few minutes to remove the grease. Some owners
prefer to completely disassemble their machines to ensure a thorough cleanup. I did not
want to remove the column or the head, but I was still able to get all of the visible
grease off.

You will need a very sturdy bench to support the mill. If you buy a
commercially-made bench, make sure it can support at least 500 lbs., since with
accessories and the mill, you can easily get to that limit - even better, I would
recommend a 600 lb. limit. A bench with wheels is a big advantage to move the mill for
cleaning up the shop or if you decide to rearrange your shop layout. In fact, I now have a
rule that every bench and tool stand in my shop be on wheels. This has been a great
feature when I want to explore new shop arrangements, or just do a thorough cleanup.

For several reasons, I decided to make my own benches for the X3 mill and C6
lathe:

Opportunity to customize size to fit my shop and height to my work style

Needed benches that would work effectively and safely with my ramp/winch system
(see below)

The downside to making your own benches, of course, is that it takes time. If
you decide to make your own, be sure that you make them strong enough to safely support
these heavy machines.

Once you have your bench in place, you may have an interesting time figuring
out how to get the mill up onto it. One tried and true method is to disassemble the mill
and reassemble it on the bench. I don't particularly like that approach since there's
always the possibility that things won't go back together just right. Another method is to
enlist the help of 3 or 4 strong, healthy guys. This could be pretty easy, but you can
quickly wear out your friends' generosity if you have to call them back a few times to
move it again. Also, I hate to think about the possibility of someone's back getting
thrown out (or something even worse happening) when lifting a heavy and awkward load such
as this.

WARNING: Moving heavy machinery can be dangerous; even
potentially life-threatening. The following descriptions are not a recommendation that you
use these techniques. Since each shop and situation is unique, you will need to take
actions appropriate to your own situation. Make sure that whatever method you choose is
safe and that you have provided a way out of danger if things do not go according to plan.
Take time to consider what might go wrong. If you are not confident in your ability to
safely move heavy equipment, get help from someone with experience, or hire a
professional. Work with a partner in case an accident occurs and emergency help is needed.

Some owners faced with this challenge have employed so-called "come-alongs" to lift their mill onto the bench. While this may
work, if you're lucky, the thought of a 350 lb., $1000 machine dangling from a
cheaply-made winch, kinda gives me the willies. I don't recommend this approach, but if
you consider it, make sure that whatever you attach the winch to can handle the weight.
Keep in mind that the stated capacity of such tools may refer to pulling a load along a
flat surface (hence the name) - NOT lifting a load off the floor - note
that the Harbor Freight link above explicitly states that the come-along is not for
lifting.

X3 mill being hauled up
the ramp onto the bench

My own solution was to build a ramp from 2x4's and plywood and then employ a
12V electric winch to haul the mill from the floor up to the bench. I had a pretty good
experience moving the C6 lathe this
way, but was a little concerned whether it would work as well for the much more top-heavy
X3 mill. In practice, it worked out very well. One thing I like about this approach is
that the machine is supported at all times by the ramp. As long as you select good-quality
lumber, free from large knots and other defects that could become a point of failure, and
avoid splitting the lumber with oversize nails or screws, the ramp can be quite strong.
Movement of the mill up the ramp is slow and controlled and you can stop in mid-move, if
necessary, and make adjustments.

Even after you get the mill up on to the bench, the fun does not end. Moving it
around on the bench without gouging up the benchtop is another thought-provoking exercise.
Thinking, I have found late in life, sometimes produces results more effectively than
swearing. Nevertheless, on a project like this, profanity, judiciously applied, seems to
help.

Along with that, I employed a small pry-bar and a variety of 1x2 and 2x3 wood
blocks, plus some thin wood shims. Working carefully and levering the mill by small
amounts on each operation, I eventually got it where I wanted - and safely. If you use a
technique like this, be sure the keep your fingers out from underneath the mill at all
times. If you need to move a wood block underneath, or out from underneath the mill, use a
piece of wood or other tool rather than your fingers to do this work.

Again, let me be clear that this is not a recommendation that you use this
approach- whatever method you select must be your own decision appropriate to your own
needs, experience and circumstances.

If you're in the market for a mid-size milling machine for hobby or light
industrial use, the X3 should certainly be on your prospect list. Over the last few years,
Sieg has established a solid reputation for manufacturing good quality machine tools at
excellent prices. Obviously, in terms of capacity, the X3 is a much more capable machine
than the mini-mill, and you will find that the extra attention to details on this mill,
such as the copious placement of oil access ports, adjustments for backlash and 10TPI
leadscrews make it a better all-around machine. At around $1000, it's a substantial
investment, but if you are serious about machining, I'm confident that you'll find it to
be a good value.

Due to its relatively large table size, a power feed is highly recommended. I
haven't had a chance to evaluate the Sieg power feed for the X3, but I would expect it to
be a real time saver when making long and/or repetitive cuts along the X-axis.